Mathematics and Physics Glossary

Magellenic clouds (Astron.), three conspicuous nebulę near the south pole, resembling thin white clouds.

Magic number, n. (Phys.) Any of the numbers, 2, 8, 20, 28, 50, 82, or 126, that represent the number of neutrons or protons in strongly bound, exceptionally stable, and abundant atomic nuclei.

Magic square, n. (Arith.) a set of numbers arranged in the form of a square so that the total of every row, column, and diagonal is the same.

Magnet, n. (Phys.) (a) The loadstone; a species of iron ore (the ferrosoferric or magnetic ore, Fe₃O₄) which has the property of attracting iron and some of its ores, and, when freely suspended, of pointing to the poles; called also natural magnet. (a) A bar or mass of steel or iron to which the peculiar properties of the loadstone have been imparted; called, in distinction from the loadstone, an artificial magnet.

§ An artificial magnet, produced by the action of a voltaic or electrical battery, is called an electro-magnet.

-- Field magnet (Phys.), a magnet used for producing and maintaining a magnetic field; used especially of the stationary or exciting magnet of a dynamo or electromotor in distinction from that of the moving portion or armature.